Hi @janopal, No, I haven't experienced any hissing sounds in my brain. Without Klonopin, I have tons of electrical activity from the brain to my body..Klonopin calms my nervous system. I get so sick without Klonopin, I feel like I'm having a seizure. Lights on white paper and certain colors drive me into madness. I saw a green metallic car and I had to look away. I started feeling like I was going into seizure mode.